"Mike Cook" <m...@NOTyahoo.com> wrote in message 
news:0...@news.eternal-september.org...
>> Older caps, such as those in buzz coils were 0.47 uF and 400 volts
>> Ford model T caps were supposed to be about the same. See a Dyke's 
>> manual.
>> Most automotive caps were 0.22 uF and 400 volts AC or 600 volts AC
>> Briggs and Stratton magnetos used the same rating forever. 0.22 uF and 
>> 400
>> volts
>> Some caps have other values, such as 0.15 uF, but 0.22 will be the most
>> common by far and will work in just about anything. The only real 
>> variable
>> is the type of mount, how long the center wire extends, and if you want a
>> connector at the end of the wire.
>
> What flavor are these caps (or what modern equivalent)? Non-polar
> electrolytic? Poly-something?

Not electrolytic. The actual design is just called wound foil/paper. They 
are not polarized. But they are designed to handle the rough temps and 
vibration next to a V8 engine.
Just go to any NAPA and ask for the cheapest universal capacitor for any car 
in the 1960s.
Look inside the box to make sure it has the wire and not a copper strip, 
some GMs came with a stiff copper strip. The last time I paid for one it was 
$1.49

Tegger  <i...@invalid.inv> wrote:
>"hls" <h...@nospam.nix> wrote in
>news:q...@giganews.com: 
>
>> Condensors seldom failed even in the old days, but occasionally they
>> did.  A person would have been a fool to pull a wrench on one of
>> those Kettering systems and not replace the condensor along with the
>> points.
>
>I remember that condensers were so cheap there was no point in tempting 
>fate by leaving the old one in when you replaced the (also cheap) points.

Yes, they came free with the points.  They still do.
--scott

-- 
"C'est un Nagra.  C'est suisse, et tres, tres precis."

In article <0...@news.eternal-september.org>,
Mike Cook  <m...@NOTyahoo.com> wrote:
>> Older caps, such as those in buzz coils were 0.47 uF and 400 volts
>> Ford model T caps were supposed to be about the same. See a Dyke's manual.
>> Most automotive caps were 0.22 uF and 400 volts AC or 600 volts AC
>> Briggs and Stratton magnetos used the same rating forever. 0.22 uF and 400 
>> volts
>> Some caps have other values, such as 0.15 uF, but 0.22 will be the most 
>> common by far and will work in just about anything. The only real variable 
>> is the type of mount, how long the center wire extends, and if you want a 
>> connector at the end of the wire.
>
>What flavor are these caps (or what modern equivalent)? Non-polar 
>electrolytic? Poly-something? 

As I mentioned earlier, they used to be oiled paper, now are mostly mylar.
--scott

-- 
"C'est un Nagra.  C'est suisse, et tres, tres precis."

"Paul Conners" <p...@gUSmail.com> wrote in message 
news:0...@news.eternal-september.org...
>> They vary.  Typically they are between .15 and .25 microFarads.
>> I know that these capacitors are subjected to test voltages up to about
>> 1800 volts.
>>
>> I have heard this discussed, but dont know the exact working voltage of
>> the units... A figure of 600 WV has been quoted, but I dont honestly 
>> know.
>>
>> If I were going to run this test (if I were having a problem), I would 
>> buy
>> a new ignition capacitor from the FLAPS and use it.  I would replace the
>> old one whatever the case.
>
> The reason I ask is that there is none in this system. A friend has 
> purchased
> a solid-state magnetic-triggered ignition module that replaces the point 
> set.
> A trigger sleeve slips over the distributer cam lobes and contains 4 small
> magnets.
>
> It is new and I can't get it to work -- no spark.

Woops!  How was this unit set up before it was modified with this
magnetically triggered module? Was it working okay when mechanical
points were used?

 I am wondering if something was lost in translation on this modification. 

> Woops!  How was this unit set up before it was modified with this
> magnetically triggered module? Was it working okay when mechanical
> points were used?
> 
>  I am wondering if something was lost in translation on this modification. 

Old points system was in the distributor prior to conversion. Yes car was 
running recently. No issues with points/capacitor ignition performance (car 
was driveable, normal). It's been a few months since then (it's a slow 
project...).

Coil was replaced as part of the conversion. I've examined both coils and 
compared resistance measurements; not much difference. 

k...@panix.com (Scott Dorsey) wrote in news:hbkeu6$jif$1
@panix2.panix.com:

> Tegger  <i...@invalid.inv> wrote:
>>"hls" <h...@nospam.nix> wrote in
>>news:q...@giganews.com: 
>>
>>> Condensors seldom failed even in the old days, but occasionally they
>>> did.  A person would have been a fool to pull a wrench on one of
>>> those Kettering systems and not replace the condensor along with the
>>> points.
>>
>>I remember that condensers were so cheap there was no point in tempting 
>>fate by leaving the old one in when you replaced the (also cheap) points.
> 
> 
> 
> Yes, they came free with the points.  They still do.


That may not have been true for all makes.

It's been a few years, but I'm pretty sure the condenser was a separate 
charge for me when I bought OEM points for my '74 Mazda.


-- 
Tegger

Tegger <i...@invalid.inv> wrote in
news:Xns9CAAC5321C512tegger@208.90.168.18: 

> k...@panix.com (Scott Dorsey) wrote in news:hbkeu6$jif$1
> @panix2.panix.com:
> 
>> Tegger  <i...@invalid.inv> wrote:
>>>"hls" <h...@nospam.nix> wrote in
>>>news:q...@giganews.com: 
>>>
>>>> Condensors seldom failed even in the old days, but occasionally
>>>> they did.  A person would have been a fool to pull a wrench on one
>>>> of those Kettering systems and not replace the condensor along with
>>>> the points.
>>>
>>>I remember that condensers were so cheap there was no point in
>>>tempting fate by leaving the old one in when you replaced the (also
>>>cheap) points. 
>> 
>> 
>> 
>> Yes, they came free with the points.  They still do.
> 
> 
> That may not have been true for all makes.
> 
> It's been a few years, but I'm pretty sure the condenser was a
> separate charge for me when I bought OEM points for my '74 Mazda.
> 
> 

unless you bought a tune up set they were always seperate.  KB

-- 
THUNDERSNAKE #9

Protect your rights or "Lose" them
The 2nd Admendment guarantees the others

"Kevin" <k...@netins.net> wrote in message 
> 
> unless you bought a tune up set they were always seperate.  KB
> 
> -- 
> THUNDERSNAKE #9

That is the way I remember it too..Havent been around a car with points
and condensor for a long time.

It was unheard of to replace points without replacing the condensor,
although most of the old condensors were probably good.

On Oct 21, 9:25=A0am, "hls" <h...@nospam.nix> wrote:
> "Kevin" <kevyNOS...@netins.net> wrote in message
>
> > unless you bought a tune up set they were always seperate. =A0KB
>
> > --
> > THUNDERSNAKE #9
>
> That is the way I remember it too..Havent been around a car with points
> and condensor for a long time.
>
> It was unheard of to replace points without replacing the condensor,
> although most of the old condensors were probably good.

to answer the OP..
most coils do not have an actual ground connection..

the current in the secondary flows to ground through the primary
circuit.  The low side of the secondary is connected to the primary.

also the condenser in the old point systems do not serve the same
purpose and are not connected the same as in a modern car.

In the old system the cap was across the points and protected the
points when they opened by absorbing the current flow... and the cap
needed to be rated for a high voltage like 400 V

In todays solid state system, the cap is usually just on the primary
+12 supply to ground to keep the ignition pulses flowing in a smaller
area loop to reduce EMI and radio interference.  The car will usually
run fine without this cap but the radio will static.  This cap just
needs to withstand the +12volts (and any surges that may be on the
+12volts which can be considerable like 80 Volts.)

Mark

"Mark" <m...@yahoo.com> wrote in message news:11500752-c5d6-

also the condenser in the old point systems do not serve the same
purpose and are not connected the same as in a modern car.

************
Sort of... The old cars may have also had noise suppression condensors.

The ignition condensor WAS connected across the points, but if you look
at the schematic you will see that this was also between the coil primary
and ground.   The condensor served, as you said, to help protect the
points, but it was more than that.  The tuned circuit also had a purpose.

New cars ignition systems may be totally different from those old Kettering
systems.

We took this on in a thread some time ago.

I am wondering if his magnetic ignition system is either faulty or hooked up
incorrectly.